Green fountain grass, or Pennisetum setaceum, is a perennial subtropical plant native to Africa, some parts of Asia and in portions of the middle east. It is a plant that is considered an invasive species in some states, such as California. In the right climate, it can spread prolifically and quickly, like most grasses. However, it isn't unusual for this plant to be purposely grown as an ornamental in places where it is legal to do so. In fact, that is how it came to grow in the US.
Pennisetum setaceum grows in tightly packed groups or clumps, with the grass growing to over four feet and up to five feet in height in some locations. The clumps can measure in excess of two feet across.
Fountain grass, though sub tropical, is quite hardy, growing in a variety of soils and withstanding high temperatures. This is a grass that is tremendously tolerant of dry conditions. It spreads both by seeding and from the roots expanding under the soil surface. The leaves do usually turn brown, like many grasses, during the cool part of the year. However, once established, fountain grass can be hard to get rid of.
According to the US Department of Agriculture, fountain grass is considered to be a noxious weed in 46 states. Established plants are also tolerant to fire and often grow in poor soils.
The flower is borne on long flower stalks and the flowers are usually slightly yellow to dark purple or black in appearance. The plant begins blooming in the early spring and can continue doing so until the middle of the autumn.
The resulting seed heads are a couple of inches long and look symmetrically fuzzy. The outer cover of the seeds are capable of being easily caught and carried in the fur of animals, contributing to the spread of the plant species. The seeds have a hard outer casing and are oblong in shape. Fountain grass has the ability to reproduce asexually. In cooler climates, the plant normally doesn't set seed but can still spread from the root culture.
Leaves of this plant species are distinctly grass-like and appear long and narrow, though not very thick. The color of the foliage can vary widely. The stems are stiff and erect.
This is a plant that can be quite attractive. However, the potential for spreading makes it a species that probably isn't worth the effort to grow. Indeed, in some areas, it is against the law to grow this kind of grass. All things considered, there is a pretty good reason for the laws prohibiting the growing of fountain grass.